Thermal conductivity of graphene nanoribbons: Effect of the edges and ribbon width

We have calculated thermal conductance of graphene nanoribbons (GNRs) and their dependence on the type of ribbon edge termination (zigzag or armchair) and the width of the ribbon, which ranges from 50 to 50 m. Our model incorporates the effect of edge roughness and includes edge roughness correlation functions for both types of termination. The dependence of thermal conductance on the width of the ribbons and relative contribution of different scattering mechanisms are also analyzed by means of the Green's function approach to the edge scattering. High temperature thermal conductance of the nanoribbons was found to be 0.15 nW/K and 0.18 nW/K (corresponding to thermal conductivity, 4641 and 5266 W/mK, respectively, for 10 m long GNRs) which is in a good agreement with the experimental results.